Blood donation
Donating blood is a simple and relatively painless procedure that can help save lives.
According to the American Association of Blood Banks, eight million volunteerdonors donate the 14 million pints of blood used in the United States each year. The blood is used to help a variety of people. Donated blood can help restore a person's blood volume after surgery, accident, or childbirth, improvethe immunity of a patient suffering from cancer or leukemia and other diseases, and improve the blood's ability to carry oxygen.
Sometimes the donated blood is used as whole blood; that is, the blood from adonor is administered in its entirety to the recipient. In other cases, theblood is separated into its components (platelets, plasma, red and white cells, and clotting factors), and administered to a patient in need of that specific component.
There is no risk of contracting disease if you donate blood, because new, sterile equipment is used for each donor. The U.S. Food and Drug Administrationhas stringent regulations concerning how blood can be collected, stored and transported, and other organizations, such as the AABB and the American Red Cross, have additional procedures to safeguard both donors and the collected blood.
To protect the nation's blood supply (and blood recipients), each donor is carefully screened to make sure he or she is in good health. At the donation center, a donor will be asked his or her name and address, and this informationwill be verified. His or her pulse, temperature and blood pressure are taken. The donor is asked if he or she has ever had a condition that might disqualify him or her as a donor; for example, hepatitis, malaria, heart disease, AIDS and most forms of cancer would make someone unsuitable as a donor. If a person's blood pressure is too high or too low, if she is pregnant, or if he orshe has had major surgery recently, he or she will be asked to wait some time before donating.
After the screening, the donor is seated in a special reclining chair or liesdown on a table. The person drawing the blood wraps a tourniquet around thedonor's upper arm; by restricting the flow of blood returning from the hand to the heart, the veins become more prominent and easier to find. The person drawing the blood inserts a needle into the vein. The needle is attached to acollection bag. The donor then lies still and quietly while the blood is collected, which takes only about 10 minutes.
When the unit, or pint, of blood is collected, the needle is removed and an adhesive bandage placed over the spot where the needle had been inserted. Thedonor is asked to lie still for a few more moments, and then offered fruit juice and perhaps cookies to replenish him or herself. Sometimes donating bloodcan cause lightheadedness, and it's important to not move too quickly or else dizziness can occur.
The whole procedure takes about an hour.
The donated blood is sealed in a special plastic bag that contains substancesthat will keep it from clotting (anticoagulants) and will preserve it. Refrigerated, whole blood is useable for 42 days. Blood components, however, can be preserved for much longer--in the case of red blood cells, up to 10 years,if frozen.
A sample of the donated blood is taken for testing. It is checked for infections diseases like AIDS and syphillis, for anemia, and, if the blood type is not already known, for blood typing. Human blood falls into three major groups, A, B, and O; the types get their names from certain molecules found on thesurface of the red blood cells. If a person receives a donation of an incompatible blood type, the blood cells can clump together, a dangerous and possibly fatal situation. Type O blood can be received by persons with A, B, or AB blood (which is why type O is sometimes called the "universal donor"), but a person with Type O blood can only Type O blood. It is also important to matchthe Rh factor of the blood, which can be positive or negative.
Anyone in good health can donate blood. It is generally recommended that thedonor be over age 17 (although some states allow younger persons to donate, with their parent's permission) and weigh at least 110 pounds. The donor's body will replenish the donated blood quickly. However, it's best to not give blood than once every two months.
There are several special donation procedures. Persons who are expecting to undergo surgery may opt to donate several pints of their own blood, which is stored and given back to them during the surgery. This is called an autologustranfusion.
A donor may give only a specified component of the blood, which is extractedby machine from the donated blood before the donated blood is returned to thedonor's body. This is a procedure called apheresis. In addition, a patient'sfamily members can donate blood specifically for the patient (as long as their blood type and Rh factors are compatible). This is called a designated ordirect donation.
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